Two transverse waves travel along the same taut string. Wave $1$ is described by y$1($x$,$ t$)=$ A sin$($kx $-$ t$),$ while wave $2$ is described by y$2($x$,$ t$)=$ A sin$($kx $+$ t $+$ $).$ The phases $($arguments of the sines$)$ are in radians, as usual, and A $=2\mathrm{.}2$ cm and $=0\mathrm{.}85$ rad.